1 /* Machine-dependent ELF dynamic relocation inline functions. Nios II version.
2 Copyright (C) 1995-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <http://www.gnu.org/licenses/>. */
22 #define ELF_MACHINE_NAME "nios2"
28 /* Return nonzero iff ELF header is compatible with the running host. */
30 elf_machine_matches_host (const Elf32_Ehdr
*ehdr
)
32 return ehdr
->e_machine
== EM_ALTERA_NIOS2
;
36 /* Return the link-time address of _DYNAMIC. Conveniently, this is the
37 first element of the GOT. */
38 static inline Elf32_Addr
39 elf_machine_dynamic (void)
44 "1: movhi\t%1, %%hiadj(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t"
45 "addi\t%1, %1, %%lo(_GLOBAL_OFFSET_TABLE_ - 1b)\n\t"
47 : "=r" (dynamic
), "=r" (tmp
));
52 /* Return the run-time load address of the shared object. */
53 static inline Elf32_Addr
54 elf_machine_load_address (void)
59 "1: movhi\t%1, %%hiadj(1b)\n\t"
60 "addi\t%1, %1, %%lo(1b)\n\t"
62 : "=r" (result
), "=r" (tmp
));
66 /* Set up the loaded object described by L so its unrelocated PLT
67 entries will jump to the on-demand fixup code in dl-runtime.c. */
69 static inline int __attribute__ ((always_inline
))
70 elf_machine_runtime_setup (struct link_map
*l
, int lazy
, int profile
)
72 extern void _dl_runtime_resolve (Elf32_Word
);
74 if (l
->l_info
[DT_JMPREL
] && lazy
)
76 /* The GOT entries for functions in the PLT have not yet been filled
77 in. Their initial contents will arrange when called to load r15 with
78 an offset into the .got section, load r14 with
79 _GLOBAL_OFFSET_TABLE_[1], and then jump to _GLOBAL_OFFSET_TABLE[2].
81 Elf32_Addr
*got
= (Elf32_Addr
*) D_PTR (l
, l_info
[DT_PLTGOT
]);
82 got
[1] = (Elf32_Addr
) l
; /* Identify this shared object. */
84 /* This function will get called to fix up the GOT entry indicated by
85 the offset on the stack, and then jump to the resolved address. */
86 got
[2] = (Elf32_Addr
) &_dl_runtime_resolve
;
92 /* Initial entry point code for the dynamic linker.
93 The C function `_dl_start' is the real entry point;
94 its return value is the user program's entry point. */
96 #define RTLD_START asm ("\
99 .type _start, %function\n\
101 /* At start time, all the args are on the stack. */\n\
104 /* Start the calculation of the GOT pointer. */\n\
106 1: movhi r8, %hiadj(_gp_got - 1b)\n\
107 addi r8, r8, %lo(_gp_got - 1b)\n\
109 /* Figure out where _dl_start will need to return to. */\n\
110 movhi ra, %hiadj(2f - 1b)\n\
111 addi ra, ra, %lo(2f - 1b)\n\
114 /* Finish the calculation of the GOT pointer. */\n\
119 /* Save the returned user entry point. */\n\
122 /* Initialize gp. */\n\
123 ldw r4, %got(_rtld_local)(r22)\n\
125 ldw r8, %call(_dl_nios2_get_gp_value)(r22)\n\
129 /* Find the number of arguments to skip. */\n\
130 ldw r8, %got(_dl_skip_args)(r22)\n\
133 /* Find the main_map from the GOT. */\n\
134 ldw r4, %got(_rtld_local)(r22)\n\
142 /* Find the first unskipped argument. */\n\
148 /* Shuffle argv down. */\n\
155 /* Shuffle envp down. */\n\
163 /* Shuffle auxv down. */\n\
172 /* Update _dl_argv. */\n\
173 ldw r2, %got(_dl_argv)(r22)\n\
176 /* Call _dl_init through the PLT. */\n\
177 ldw r8, %call(_dl_init)(r22)\n\
180 /* Find the finalization function. */\n\
181 ldw r4, %got(_dl_fini)(r22)\n\
183 /* Jump to the user's entry point. */\n\
187 /* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
188 PLT entries should not be allowed to define the value.
189 ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to one
190 of the main executable's symbols, as for a COPY reloc. */
191 #define elf_machine_type_class(type) \
192 ((((type) == R_NIOS2_JUMP_SLOT \
193 || (type) == R_NIOS2_TLS_DTPMOD \
194 || (type) == R_NIOS2_TLS_DTPREL \
195 || (type) == R_NIOS2_TLS_TPREL) * ELF_RTYPE_CLASS_PLT) \
196 | (((type) == R_NIOS2_COPY) * ELF_RTYPE_CLASS_COPY) \
197 | (((type) == R_NIOS2_GLOB_DAT) * ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA))
199 /* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
200 #define ELF_MACHINE_JMP_SLOT R_NIOS2_JUMP_SLOT
202 /* The Nios II never uses Elf32_Rel relocations. */
203 #define ELF_MACHINE_NO_REL 1
204 #define ELF_MACHINE_NO_RELA 0
206 /* Fixup a PLT entry to bounce directly to the function at VALUE. */
208 static inline Elf32_Addr
209 elf_machine_fixup_plt (struct link_map
*map
, lookup_t t
,
210 const Elf32_Rela
*reloc
,
211 Elf32_Addr
*reloc_addr
, Elf32_Addr value
)
213 return *reloc_addr
= value
;
216 /* Return the final value of a plt relocation. */
217 static inline Elf32_Addr
218 elf_machine_plt_value (struct link_map
*map
, const Elf32_Rela
*reloc
,
224 /* Names of the architecture-specific auditing callback functions. */
225 #define ARCH_LA_PLTENTER nios2_gnu_pltenter
226 #define ARCH_LA_PLTEXIT nios2_gnu_pltexit
228 #endif /* dl_machine_h */
232 /* Perform the relocation specified by RELOC and SYM (which is fully resolved).
233 LOADADDR is the load address of the object; INFO is an array indexed
234 by DT_* of the .dynamic section info. */
236 auto inline void __attribute__ ((always_inline
))
237 elf_machine_rela (struct link_map
*map
, const ElfW(Rela
) *reloc
,
238 const ElfW(Sym
) *sym
, const struct r_found_version
*version
,
239 void *const reloc_addr_arg
, int skip_ifunc
)
241 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
242 const unsigned int r_type
= ELF32_R_TYPE (reloc
->r_info
);
244 if (__glibc_unlikely (r_type
== R_NIOS2_RELATIVE
))
245 *reloc_addr
= map
->l_addr
+ reloc
->r_addend
;
246 else if (__glibc_unlikely (r_type
== R_NIOS2_NONE
))
250 const Elf32_Sym
*const refsym
= sym
;
251 struct link_map
*sym_map
= RESOLVE_MAP (&sym
, version
, r_type
);
252 Elf32_Addr value
= sym
== NULL
? 0 : sym_map
->l_addr
+ sym
->st_value
;
258 /* This can happen in trace mode if an object could not be
261 if (sym
->st_size
> refsym
->st_size
262 || (sym
->st_size
< refsym
->st_size
&& GLRO(dl_verbose
)))
266 strtab
= (const void *) D_PTR (map
, l_info
[DT_STRTAB
]);
268 %s: Symbol `%s' has different size in shared object, consider re-linking\n",
269 rtld_progname
?: "<program name unknown>",
270 strtab
+ refsym
->st_name
);
272 memcpy (reloc_addr_arg
, (void *) value
,
273 MIN (sym
->st_size
, refsym
->st_size
));
275 case R_NIOS2_GLOB_DAT
:
276 case R_NIOS2_JUMP_SLOT
:
277 # ifdef RTLD_BOOTSTRAP
278 /* Fix weak undefined references. */
279 if (sym
!= NULL
&& sym
->st_value
== 0)
285 #ifndef RTLD_BOOTSTRAP
286 case R_NIOS2_TLS_DTPMOD
:
287 /* Get the information from the link map returned by the
290 *reloc_addr
= sym_map
->l_tls_modid
;
293 case R_NIOS2_TLS_DTPREL
:
294 *reloc_addr
= reloc
->r_addend
+ TLS_DTPREL_VALUE(sym
);
297 case R_NIOS2_TLS_TPREL
:
300 CHECK_STATIC_TLS (map
, sym_map
);
301 *reloc_addr
= reloc
->r_addend
+ TLS_TPREL_VALUE(sym_map
, sym
);
305 case R_NIOS2_BFD_RELOC_32
:
306 *reloc_addr
= value
+ reloc
->r_addend
;
310 _dl_reloc_bad_type (map
, r_type
, 0);
316 auto inline void __attribute__((always_inline
))
317 elf_machine_rela_relative (ElfW(Addr
) l_addr
, const ElfW(Rela
) *reloc
,
318 void *const reloc_addr_arg
)
320 Elf32_Addr
*const reloc_addr
= reloc_addr_arg
;
321 *reloc_addr
= l_addr
+ reloc
->r_addend
;
324 auto inline void __attribute__((always_inline
))
325 elf_machine_lazy_rel (struct link_map
*map
,
326 ElfW(Addr
) l_addr
, const ElfW(Rela
) *reloc
,
329 Elf32_Addr
*const reloc_addr
= (void *) (l_addr
+ reloc
->r_offset
);
330 if (ELF32_R_TYPE (reloc
->r_info
) == R_NIOS2_JUMP_SLOT
)
331 *reloc_addr
+= l_addr
;
333 _dl_reloc_bad_type (map
, ELF32_R_TYPE (reloc
->r_info
), 1);
336 #endif /* RESOLVE_MAP */